Synthesis of 2-Amino-1-cyanoazulenes: Substituent Effect on 2H-Cyclohepta[b]furan-2-ones toward the Reaction with Malononitrile
摘要:
3-Substituted 2-amino- 1-cyanoazulene derivatives were prepared by the reaction of 2H-cyclohepta[b]furan-2-ones with malononitrile in the presence of triethylamine as a base. The great influence of the substituent at their 3-position on the reactivity to form the 2-aminoazulene derivatives was revealed. The intramolecular charge transfer (ICT) characters of 2-amino- 1-cyano-3-vinylazulenes were investigated by UV/Vis spectroscopy and theoretical calculations. The structure of compounds 13b and 14b was clarified by single crystal X-ray analysis.
A Novel Approach to 5,5’-Diisopropyl-3,3’-bi-2H-cyclohepta[b]furan-2-one
摘要:
5-Isopropyl-2H-cyclohepta[b]furan-2-one (1) reacted with DMSD to give dimethyl(5-isopropyl-2-oxo-2H-cyclohepta[b]furan-3-yl)sulfonium trifluoromethanesulfonate (2), which was treated with E(t)3N to give 5-isopropyl-3-methylthio-2H-cyclohepta[b]furan-2-one (3). Sulfide 3 was oxidized with mCPBA to give sulfoxide 4 and sulfone 5. The salt 6 which comes from the treatment of 4 with Tf2O converted to an unexpected product, 5,5'-diisopropyl-3,3'-bi-2H-cyclohepta[b]furan-2-one (7), thermally.